gulp-progeny-mtime

A gulp plugin to update the mtime of a file in a stream to the latest mtime of its progeny.

This is useful if you want to use gulp-newer to determine if you regenerate a file that itself includes other files. You need to take into account the modification times of all of the progeny of the file you're testing. This plugin uses progeny to find decendent files, and replaces the mtime of the parent file with the latest of the decendents. This enables gulp-newer to detect changes in decendent files as if they affected the mtime of the parent.

Gulp example

Imagine you have main.less that includes components/header.less.

@import "components/header";

You pass main.less through the less plugin to compile it, and it includes the contents of components/header.less. Then you modify components/header.less. Without gulp-progeny-mtime, gulp-newer prevents main.less from being recompiled as its mtime hasn't changed. With gulp-progeny-mtime, the mtime of main.less is updated in the stream to match components/header.less and the file is recompiled.

var gulp = require('gulp');
var less = require('gulp-less');
var newer = require('gulp-newer');
var progenyMtime = require('gulp-progeny-mtime');
 
gulp.src('*.less')
    .pipe(progenyMtime())
    .pipe(newer({ dest: 'build', ext: '.css'}))
    .pipe(less())
    .pipe(gulp.dest('build'));

Options

You can pass an optional options object, which is passed straight to progeny. See progeny for documentation.

Install

$ npm install --save-dev gulp-progeny-mtime